The present invention relates to a suspension for supporting a head section of a disk drive stored in an information processing apparatus such as a personal computer, and more particularly, to an improvement of a suspension end portion.
A head section of a magnetic disk drive or the like that uses a hard disk includes a slider. Data are recorded in or retrieved from the disk by means of a transducer that is stored in the slider. The slider is supported by a suspension in a manner such that it can be lifted above the surface of the disk.
Conventionally, disk drives of this type are provided with means for evacuating the slider to a region outside the tracks of the disk when the disk is stopped from rotating. CSS (contact-start-stop) and L/UN (loading/unloading) systems are known examples of this evacuating means.
In the CSS system, the distal end portion of the suspension is moved to the inner peripheral portion of the disk when the disk is stopped. In order to prevent the slider from clinging to the surface of the stopped disk, according to the CSS system, the surface of the inner peripheral portion of the disk is roughened to a certain degree. Accordingly, the inner peripheral portion of the disk cannot be used as a recording area (tracks), so that the disk cannot enjoy a satisfactory recording capacity. The recording capacity may be increased by reducing the fly height of the slider, for example. According to the CSS system, however, the rough surface of the inner peripheral portion of the disk prevents the reduction of the fly height.
In the L/UN system or ramp-load system, on the other hand, a plastic ramp block is disposed beside the disk. When the disk is stopped from rotating, the suspension moves to a refuge zone beside the disk so that its distal end portion runs on the ramp block. Thereupon, the suspension is supported by the ramp block. This L/UN system does not require the surface of the inner peripheral portion of the disk to be roughened. Therefore, the fly height can be reduced, and the recording capacity can be made greater than in the case of the CSS system. According to the L/UN system, moreover, the inner peripheral portion of the disk can be also used as a recording area, thus facilitating augmentation of the capacity.
In the loading/unloading system, however, the contact between the suspension and the ramp block involves some problems. As the suspension repeatedly touches and leaves the ramp block, for example, a part of the plastic ramp block may be shaved, thereby producing fine contaminants. As the coefficient of friction between the suspension and the ramp block changes with time, moreover, control of the suspension may become difficult in some cases. Since the friction coefficient of the contact region between the suspension and the ramp block changes, furthermore, driving power for the movement of the suspension on the ramp block may become unstable.